A long hallway at A. MacArthur Barr Middle School, in Nanuet, NY, doubles as a dragstrip for carbon-dioxide-powered model cars. Like the Cub Scouts’ Pinewood Derby, CO2 racing is a fun way for young people to discover design and engineering principles. At Barr Middle School, the dragster race has become a rite of passage.
“They look forward to eighth grade,” said technology teacher and racing commissioner Vinny Garrison. “It’s a project that kids remember.” A showcase outside the old woodshop has a selection of wooden cars and 3D printed wheels, as well as a leaderboard showing the fastest 65-foot runs of the school year — and of all time.
Over the course of seven weeks, each eighth grader will shape a footlong wood block into a car. Each car has a compartment in the back big enough to hold a CO2 cartridge usually used for whipping cream or carbonating water, and beyond that anything goes. The competitive students go for long and lean, while others will shape theirs like a flower or their favorite animated character.
The wheels also take many different forms. Other schools with the CO2 dragster in the curriculum order stock wheels in bulk, but each Barr Middle School racer designs a set of wheels in 3D design software and prints them on a MakerBot Replicator Desktop 3D Printer. Whether form or function is a priority, the 3D printer helps. Those eager to challenge the all-time record — which has dropped from 0.701 to 0.643 seconds in the MakerBot era — craft wheels weighing as little as eight-tenths of a gram. (Stock wheels can weigh as much as five grams each.) Other students create elaborate patterns worthy of a custom-rim shop.
Barr Middle School’s approach to the CO2 dragster project appeals to a wide range of students, whether their interests are engineering or design, competition or craft. It is also a deft integration of older and newer technologies: Students use laptops on shop tables with vises, and the MakerBot Replicator takes its place among the band saw, the rasp, and sandpaper. In the fall, Garrison’s class will be working with a MakerBot Replicator Mini as well.
“I have kids engineering parts—parts that don’t exist,” Garrison says. “They are going to get to college and the teacher is going to be, ‘Oh, you’re good. You know how to do this.’”